5 files changed, 37 insertions, 1 deletions

diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S
index dd63d4775398..7e639f78b0b9 100644
--- a/arch/i386/kernel/syscall_table.S
+++ b/arch/i386/kernel/syscall_table.S
@@ -317,3 +317,4 @@ ENTRY(sys_call_table)
         .long sys_tee                   /* 315 */
         .long sys_vmsplice
         .long sys_move_pages
+        .long sys_getcpu
diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 30ed0f6f4a2b..32fd32bea07c 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -713,4 +713,5 @@ ia32_sys_call_table:
         .quad sys_tee
         .quad compat_sys_vmsplice
         .quad compat_sys_move_pages
+        .quad sys_getcpu
 ia32_syscall_end:               
diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h
index fc1c8ddae149..565d0897b205 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -323,10 +323,11 @@
 #define __NR_tee                315
 #define __NR_vmsplice           316
 #define __NR_move_pages         317
+#define __NR_getcpu             318
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 318
+#define NR_syscalls 319
 
 /*
  * user-visible error numbers are in the range -1 - -128: see
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 008f04c56737..3f0f716225ec 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -53,6 +53,7 @@ struct mq_attr;
 struct compat_stat;
 struct compat_timeval;
 struct robust_list_head;
+struct getcpu_cache;
 
 #include <linux/types.h>
 #include <linux/aio_abi.h>
@@ -596,5 +597,6 @@ asmlinkage long sys_get_robust_list(int pid,
                                     size_t __user *len_ptr);
 asmlinkage long sys_set_robust_list(struct robust_list_head __user *head,
                                     size_t len);
+asmlinkage long sys_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *cache);
 
 #endif
diff --git a/kernel/sys.c b/kernel/sys.c
index e236f98f7ec5..3f894775488d 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -28,6 +28,7 @@
 #include <linux/tty.h>
 #include <linux/signal.h>
 #include <linux/cn_proc.h>
+#include <linux/getcpu.h>
 
 #include <linux/compat.h>
 #include <linux/syscalls.h>
@@ -2062,3 +2063,33 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
         }
         return error;
 }
+
+asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep,
+                           struct getcpu_cache __user *cache)
+{
+        int err = 0;
+        int cpu = raw_smp_processor_id();
+        if (cpup)
+                err |= put_user(cpu, cpup);
+        if (nodep)
+                err |= put_user(cpu_to_node(cpu), nodep);
+        if (cache) {
+                /*
+                 * The cache is not needed for this implementation,
+                 * but make sure user programs pass something
+                 * valid. vsyscall implementations can instead make
+                 * good use of the cache. Only use t0 and t1 because
+                 * these are available in both 32bit and 64bit ABI (no
+                 * need for a compat_getcpu). 32bit has enough
+                 * padding
+                 */
+                unsigned long t0, t1;
+                get_user(t0, &cache->t0);
+                get_user(t1, &cache->t1);
+                t0++;
+                t1++;
+                put_user(t0, &cache->t0);
+                put_user(t1, &cache->t1);
+        }
+        return err ? -EFAULT : 0;
+}